Tailstock



J. J. THACHER I TAILSTOCK Filed April 9, 1923 INVENTOR ATTORNEY i Fatented July 7 1925.

UNITED STA rss [PATENT OFFICE.

JOHN J. TEACHER, OF WETHEBSFIELD, CONNECTICUT, ASSIGNOR T0 PRATT 8a WHIT- NEY COMPANY, OF -NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

TAILSTOCK.

Application filed April 9,

To all whom it man] concern.

Be it known that I, JOHN J. THACHER, a citizen of the United States, and a resident of Wethersfield, in the county of Hartford and State of Connecticut, have invented certain new and useful, Improvements 1n Tailstocks, of which the following is a specification.

This invention relates to tailstocks and as illustrated theinvention is particularly applicable for use in connection with or as a part of an. automatic lathe of the typeset forth in my Patent No. 1,507,265, dated September 2, 1924. The primary object of my invention is to provide an improved automatic tailstock mechanism wherein the spindle is first engaged with the work piece and is thereafter securely clamped in such position, such mechanism being particular-- ly adaptedfor use in combination with automatic lathes.

It is an object of my invention to provlde an improved automatic tailstock mechanism and manual means in combination therewith for rendering the clamping means inoperative without disturbing the adjustment of the automatic clamping mechanism.-

Another object of my invention is to provide improved spindle clamping means operated from beneath the spindle and improved means for automatically reciprocating the spindle and operating the clamping means from the main cam shaft of the machine.

More specifically my invention comprises a transversely extending clamping element in 'connection with the tailstock spindle and means frictionally connected to the spindle and adapted in its forward movement to first engage the spindle centerwith the worli and thereafter by a continued movement to rotate the clamping element sufiicientl to bind'the spindle against movement. X further object of my invention is to provide an improved mechanism of this type and c0- operating indicia thereon for indicating the proper relative assembly of the spindle and its cooperating parts prior to the tooling operation. j

With the above and other objects in view, my invention consists in the features of construction and operation set forth in the following specification and illustrated in the accompanying drawing. In such drawing annexed hereto anu forming a part of this 1923. Serial No. 630,977.

specification, I have shown one embodiment of my invention but it will be understood that the invention can be otherwise embodied and that the drawing is not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose. 3 Referring to the figures of the drawing:

Figure 1 is a front elevation of my improved tailstock and its operating'mechanism.

Fig. 2 is a rear end elevation thereof.

Fig. 3 is a detail sectionalview taken on line 33 of Fig. 1.

Fig. 4 is a transverse sectional view taken on line 44 of Fig. 3.

Fig. 5 is a rear end elevation partially in section on line 55 of Fig. 1. Referring more specifically to the drawmg by reference characters, 1 indicates the body or frame portion of my improved tail- .stock which is adjustably mounted on the bed 2 in the usual manner. A clamping bolt and handle 3 are provided for securing the tailstock in its adjusted position on the bed. The upper portion 1 of the tailstook can be adjusted transversely on the lower portion 1 thereof by means of bolts 4 and 4. Slidably mounted in a longitudinally extending guideway 5 in the front side of the frame 1 is a tailstock spindle 6 supporting a work engaging center 7 in its forward end. It will be noted that the exposed surface of the spindle is flat and flush with the frontface of the frame 1. The spindle is reciprocated by an element 8 frictionally mounted on the rear. end thereof. The frictional engagement between the element and the spindle can be regulated by means of a screw 9 threaded into the element and engaging a friction plate 10.

The upper ends of a pair of arms 11 supported on a plate 12 on the bed 1 provides a pair of guideways for an elongated reciprocating member 13. This member 1 has oppositely disposed longitudinal ribs 14 at one end thereof riding in grooves 15 in the said arms. A rod 16 pinned to the element 8 at 17 extends telescopically into the member 13 and may be adjustably secured therein by means of set screws 18. Such connection provides for an adjustment of the tailstock on the bed 2. Furthermore, the member 13 is reversible end to end whereby its bed for operating on short work.

elongated end may extend forwardly instead of rearwardly as-illustrated in Fig. 1. Such reversibility permits operative engagement with the mechanism when the tailstoc-k' is ad justed inwardly to a great distance on the It will furthermore be understood that this tele-- scopic arrangement provides for the desired adjustment of the tailstock on the bed without using an objectionably long bar 16 extending rearward from the tailstock.

Pivoted between the arms 11 at 19 is a lever 20, the upper end of which engages within a notch 21 in the member 13. A roller 22 on the lower end of the. lever rides on a cam drum 23 and is adapted to be oscillated by cam strips 24 and 25. This cam drum is mounted on one end of the main cam shaft 26. It will be seen that as the drum 23 rotates, the lever 20. will be oscillated and the element 8 reciprocated. collar 27 adjustably mounted on the forward end of the spindle limits the rearward movement. thereof.

The spindle 6 is slidably mounted on a plate 28 secured to the ta-ilstock by means of screws 29 adjacent its ends. The plate is slotted transversely at 30 whereby to weaken the inner portion thereof for a purpose hereinafter described. The plate is furthermore provided with a notch 31 therein between the slots 30. Rotatably mounted in the tailstocktransversely of the spindle and extending into the notch 31 is a bolt 32. One end of this bolt is notched at 33 for receiving the spindle 6 and plate 28. A washer and check nuts 34 secure the bolt in place and the clamping elfectof the bolt on the plate 28 and the spindle may be adjusted by rotatably adjusting the nuts 34.

Mounted in a transverse bore in the bolt 32.is a rearwardly extending arm 35, the arm being secured in the bolt by a set screw 36. Pivotally mounted on the element 8 at' 37 is a bell crank having a downwardly extending arm 38 and an upwardly extending 4 or the inoperative position shown in dot and dash lines therein. In the operative po sition the arm 39 engages astop or abutment 41 and likewise the arm 38 engages an abutment 41 in the inoperative position as illustrated. Occasionally it becomes necessary to manually remove a piece of work from the spindle or to manually adjust the spindle. For such purposes, the spindle may at any time be unclarnped merely by moving the handle 39 from the position shown in full lines to the position shown in dotted lines in Fig. 4. Such operation merely renders the roller 40 ineffective on the clamping arm 35 and in no way disturbs the adjusttailstock.

.end of the tailstocki ment of the automatic clamping mechanism. The spindle may be reclamped merely by pushing the handle back to its original position.

The-front fiat face of the spindle is flush with the tailstock and none of the clamping parts project beyond such face to interfere with the operation of the tool. Such construction is obtained and the spindle securely clamped by the novel engagement of the clamping means against the edge of the spindle. It should furthermore be noted that a greater clamping rigidity is obtained by placing the clamping plate beneath the In the tooling operation the thrust of the tool on the work is upward'and therefore tends to move the spindle 6 upwardly. The clamping plate 28, however, holds the spindle secured in its uppermost position in the guidway 5 whereby to rigidly A resist the upward thrust of the tool.

Since the work piece forms the stop limiting the forward movement of the spindle, it is very essential that the various operating parts of the mechanism be properly assembled relative to such piece prior to the tooling operation thereon. For this purpose, I provide zero marks 42 and 43 on the spindle for cooperating with zero marks 42 and 43 respectively on the frame 1 and element 8. lVhen originally setting the mechanism preparatory to operating on blanks of a certain length, one of the blanks W is placed between the centers and the spindle 6 brought forwardly to engage its center 7 therewith. The tailstock frame 1 is then clamped to the bed with the zero marks 42 in -register.- lVith the set screws 18 loosened,

ltl

the member 13 is moved to its extreme forward position (toward the tailstock). The element 8 is then frictionally clamped to the spindle with the zero marks 43 in register and the screws 18 are tightened. As so positioned, the spindle and the automatic clamping mechanism are in the spindle clamping position.

It should be understood that in the operation of the mechanism, the forward movement of the spindle is limited by the engagement of the center 7 with the work andrearward movement of the spindle is limited by the collar. 27 engaging against the forward Furthermore, the spindle reciprocating member 8 reciprocates further in each direction than does the spindle, the frictional connection at 10 per mitting the member 8 to slip on the spindle. In Fig. 1, the parts are shown in the forward position in full lines and in the rearward position in dotted lines. As indicated in such figure, the spindle reciprocates through a distance a and the member 8 reciprocates through a distance 6.

The operation of the mechanism is as follows, it being understood that ordinarily all the spindle, and rides upon the free end of the arm 35, thus forcing such arm downwardly and slightly rotating the spindle clamping bolt 32. Such rotation of the bolt forces the weakened portion of the plate 28 upwardly into clamping engagement with the spindle and holds the same against longitudinal movement. It. will be understood that the notched engaging surfaces of the plate 28 and bolt 32 are so arranged as to provide this clamp-ing action. The parts remain in this relative clamped position while the tooling operation is being performed on Y the work. At the end of such operation the cam strip 25- engages the roller 22 and moves the member 8 rearwardly. Such member first slides on the spindle and the roller rides off the arm 35. The spindle nowbeing unclamped, the same is drawn rearwardly with the member 8. All these operations are. performed automatically from the cam drum 23 which is mounted on and rotates with the main cam shaft 26.

What I claim is:

1. A lathe tailstock comprising in combination, a frame, a spindle longitudinally movable therein, means frictionally connected to the spindle for so moving the same, a rookable spindle clamping element adjacent thespindle, and means cooperating with the clamping element and the first named means whereby forward movement of the first named means first moves the spindle to the work and by a continued movement thereafter rocks the clamping element about its longitudinal axis sufiiciently to bind the spindle.

2. A lathe tailstock comprising in combination, a frame, a spindle longitudinally movable therein, means frictionally connected to the spindle for so moving the same, a rockable' spindle clamping element extending transversely of the spindle, a laterally extending arm connected to .the clamping element, forward movement of the said means being adapted to first engage the spindle with the work, and means on the first named means for engaging the arm and rocking the clamping element sufliciently to bind the spindle upon continued forward movement of the first said means.

3. A lathe tailstock comprising in combi- The member 8 thereafter connation, a frame, a spindle longitudinally movable therein, means including a pivoted lever having one end frictionally connected to the spindle for reciprocating the same longitudinally, cam mechanism engaging the other end of the lever to oscillate the same about its pivot, a spindle clamping element adjacent the spindle, means cooperating with the clamping element and the first named means whereby forward movement of the first named means first moves the spindle to the work and by a continued movement therafter moves the clamping element sufficiently to bind the spindle, and an adjustable collar on the spindle for limiting the backward movement thereof.

4. A lathe tailstock comprising in combination, a frame, a spindle longitudinally movable therein, a plate connected to the frame and engaging the spindle, the plate being slotted to weaken the spindle engaging portion thereof, an element movably mounted in the frame and engaging the weakened portion of theplate, and means for \slightly moving the element to force the weakened portion of the plate into clamping engagement with the spindle.

5. A lathe tailstock comprising in combination, a frame, a spindle longitudinally movable therein, a plate having its ends connected to the frame, and a central portion thercof notched out and engaging the spindle, the plate being slotted at opposite sides 'of the notched portion to weaken the same,

anelement rotatably mounted in the frame and engaging within the notched out portion of the plate, and means for'slightly rotating the element to force the weakened portion of the plate into clamping engagement with the spindle.

6. A lathe tailstock comprising in combination, a frame, a spindle longitudinally movable therein, a plate connected to the frame and engaging the spindle, an el;ment rotatably mounted in the frame and engaging the plate, and means for moving the spindle to engage the work and thereafter slightly rotating the element to force the plate'into clamping engagement with the spindle.

7. A lathe tailstock comprising in combination, a frame, a spindle longitudanally movable therein, power operated means for automatically moving the spindle longitudinally to engage a piece of work and for thereafter securely clamping the spmdle against movement,'and manual means for rendering the clamping means lnoperative without disturbing the adjustment of the automatic clamping mechanism.

8. A lathe tailstock comprising in combination, a frame, a spindle longitudinally movable therein, clamping means for securing the spindle against movement, means for adjusting the clamping means to vary its clamping action on the vspindle, power operated means for automatically moving the spindle longitudinally'to engage a work piece and for thereafter operating the clamping means to clamp the spindle against movement, and manual means for rendering the clamping means inoperative without disturbing the said adjusting means.

9. A lathe tailstock comprising in combination, a frame, a spindle longitudinally movable therein, means frictionally connected to the spindle for reciprocating the same longitudinally, spindle clamping means adjacent the spindle, means for adjusting the clamping means to vary its movable therein, means frictionally connected to the spindle for so moving the same, a r'ockable spindle clamping element extending transversely of the spindle, a laterally extending arm connected to the clamping element, forward movement of the said means being adapted to first engage the spindle with the work, and means on the first named means for engaging the arm and rocking the clamping element sufficiently to bind the spindle upon continued forward movement of the first said means, the second named means being manually disengageable from the arm to release the clamp.

11.-A lathe tailstock comprising in combination, a frame having a longitudinally extending guideway in one side thereof, a spindle slidably mounted therein and having an exposed fiat surface substantially flush with the frame, clamping means engaging one edge of the spindle, and power operated means for reciprocating the spindle longitudinally, the last said means in its forward movement operating first to move the spindle into engagement with awork' piece and thereafter forcing the clamping means into clamping engagement with the spindle, and in its backward movement operating first to release the clamping means and thereafter withdrawing the spindle from the work.

12. A lathe tailstock comprising in combination, a frame having a longitudinally extending guideway in one side thereof, a spindle slidably mounted therein and having an exposed flat surface substantially flush with the frame, a clamping plate engaging the lower edge of the spindle, and

power operated means for reciprocating the spindle longitudinally, the said meansin its forward movement operating first to move the spindle into engagement with 'a work piece and thereafter forcing the clamping plate upwardly into clamping engagement with the spindle and in its backward movement operating first to release the clamping plate and thereafter withdrawing the spindle from the work.

13. A lathe ta'ilstock comprising in combination, a frame having a longitudinally extending guideway in one side thereof, a spindle slidably mounted therein and having an exposed flat surface substantially flush with the frame, a clamping plate engaging one edge of the spindle, a clamping element mounted in the frame and engaging the plate, means for adjusting the operative engagement of the element with the plate, and power operated means for reciprocating the spindle longitudinally, the said means in its forward movement operating first to move the spindle into engagement with a work piece and thereafter forcing the clamping plate into clamping engagement with the spindle and in its backward movement operating first to-relcase the clamping plate and thereafter withdrawing the spindle from the work.

14. A lathe tailstock comprising in combination, a frame, a spindle longitudinally movable therein, means providing a guide way rearwardly of thespindle, an element movable in the guideway and elongated at one end thereof longitudinally of the spindle, a rod operatively connected to the spindle and extending into the element, means for 'adjustably securing the rod in the element, the element being reversible whereby its elongated end may project toward or away from the tailstock, means for reciprocating the element and spindle, and means for automatically clamping the spindle in its work engaging position.

15. A lathe tailstock comprising in combination, a frame, a spindle longitudinally movable therein, means frict'ionally connected to the spindle for reciprocating the same longitudinally, a rod connected to the said means, an elongated element longitudinally adjustable on the rod, the element being re versible end to end whereby its free end may extend toward or away from the tailstock,

a power shaft, an operative connection from the shaft to the element for reciprocating the same longitudinally, and power operated means for clamping the spindle after the same has been moved forwardly into engagement with a piece of work.

16. A lathe tailstock comprising in combination, a frame, a spindle longitudinally movable therein, means frietionally connected to the spindle for reciprocating the same longitudinally, means connected to the first named means and extending rearwardly therefrom in a direction parallel with the spindle, an element longitudinally adjustable on the second mentioned means, a pivoted lever having one end connected to the said element, cam means for engaging the other end of the lever for oscillating the same, and power operated means for clamping the spindle after the same has been moved forwardly into engagement with a piece of work. i

17. A lathe tailstock comprising a combination, a frame, a spindle longitudinally movable therein, spindle clamping means, power operated means for reciprocating the spindle longitudinally, the mechanism being adapted to automatically move the spindle into engagement with a work piece and to securely clamp the spindle against movement and to thereafter release the clamp and withdraw the spindle, and means for indicating the proper relative assembly of the vari ous parts prior to the tooling operation.

18. A lathe tailstock comprising in come bination, a frame, a spindle longitudinally movable therein, means frictionally connected to the spindle for reciprocating the same,

spindle clamping means, means cooperating with the first two named means whereby forward movement of the first named means first moves the spindle to the work and by continued movement thereafter operates the clamping means to clamp the-spindle against movement, and means for indicating the proper relative assembly of the spindle in the tailstock and of the first named means on the spindle prior to the tooling operation.

19. A lathe tailstock comprising in combination, a frame, a spindle longitudinally movable therein, means frictionally connected to the spindle for reciprocating the same, spindle clamping means, means cooperating with the first two named means whereby forward movement of the first named means first moves the spindle to the work and by continued movement thereafter operates the clamping means to clamp the spindle against movement, and indicia on the spindle and its cooperating parts for indicating the proper relative assembly of the spindle and such parts prior to the tooling operation.

In testimony whereof, I hereto afiix my signature.

JOHN J. THACHER. 

